Rapid Gas Generating Pyrotechnical Composition and Method for Obtaining Same
The subject-matter of the present invention is: pyrotechnic compositions generating gases, whereof at least 95% by mass of the charges are constituted by constitutive ingredients hereinbelow: a reducing charge in the form of at least one organic nitrogen compound; an oxidizing charge in the form of at least one basic metal nitrate; and less than 30% by mass of a second oxidizing charge in the form of at least one alkaline metal perchlorate; and which are obtained via a dry roller compacting step of a pulverulent mixture essentially constituted by said powder ingredients; and also the method for obtaining such compositions. The compositions of the invention have interesting combustion speeds.
1 . A pyrotechnic composition generating gases, whereof at least 95% by mass of the charges are constituted by the constitutive ingredients hereinbelow:
a reducing charge in the form of at least one organic nitrogen compound;
an oxidizing charge in the form of at least one basic metal nitrate; and
less than 30% by mass of a second oxidizing charge in the form of at least one alkaline metal perchlorate; and
which is obtained via a dry roller compacting step of a pulverulent mixture essentially constituted by said powder ingredients.
2 . The composition according to claim 1 , in the form of shaped objects, granules, pellets or extruded monolithic blocks.
3 . The composition according to claim 1 , wherein that said at least one organic nitrogen compound is selected from guanidine nitrate, nitroguanidine, guanyl urea dinitramide and their mixtures; in that said at least one organic nitrogen compound consists advantageously of guanidine nitrate.
4 . The composition according to claim 1 , wherein that said at least one basic metal nitrate is selected from basic copper nitrate, basic zinc nitrate, basic bismuth nitrate and their mixtures; in that said at least one basic metal nitrate consists advantageously of basic copper nitrate.
5 . The composition according to claim 1 , wherein that said at least one alkaline metal perchlorate is selected from potassium perchlorate, sodium perchlorate and their mixtures; in that said at least one alkaline metal perchlorate consists advantageously of potassium perchlorate.
6 . The composition according to claim 1 , wherein that said at least one organic nitrogen compound is present at a rate of 45 to 65% by mass.
7 . The composition according to claim 1 , wherein that said at least one basic metal nitrate is present at the rate of 15 to 35% by mass.
8 . The composition according to claim 1 , wherein that said at least one alkaline metal perchlorate is present at the rate of 10 to 25% by mass.
9 . The composition according to claim 1 , wherein that it is in the form of extruded monolithic blocks and in that said blocks include up to 10% by mass of a dry gel.
10 . The composition according to claim 9 , wherein that said gel is selected from cellulosic gels, gels obtained from acrylic elastomers, ethylene-vinyl-acetate copolymers with high acetate rate, polyester polymers and their mixtures.
11 . The composition according to claim 9 , wherein that said gel is sodium carboxymethyl cellulose gel.
12 . A method for obtaining a pyrotechnic composition generating gases, wherein it comprises:
dry mixing of powders consisting for at least 95% by mass of a pulverulent reducing charge in the form of at least one organic nitrogen compound, a pulverulent oxidizing charge in the form of at least one basic metal nitrate and less than 30% by mass of a second oxidizing pulverulent charge in the form of at least one alkaline metal perchlorate; and
dry roller compacting of the resulting mixture of powders.
13 . The method according to claim 12 , wherein that said powders have granulometry less than or equal to 40 μm.
14 . The method according to claim 12 , wherein that it further comprises dry granulation of the compacted mixture of powders for generating granules.
15 . The method according to claim 14 , wherein that it further comprises pelleting of said granules.
16 . The method according to claim 14 , wherein that it further comprises mixing said granules with a gel and extruding said gel loaded with said granules.
17 . The method according to claim 12 , wherein that it comprises recycling fines generated during the dry compacting phase and/or during the granulation phase.
18 . The method according to claim 14 , wherein that it comprises recycling fines generated during the granulation process.